Where the size and location of the equipment to be welded makes preheating impossible, but the designe is such that expansion and contraction caused during welding will warp or highly stress the metal, the following steps should be observed:
(1)Pause between passes to allow heat to dissipate.
(2)Lightly peen with a hammer before each deposit solidifies and while it is hot.
(3)By making separate weld deposits and then going back over and filling in,you will avoid localized excess heat.
Do not weld on a surface that has been prepared by a grinding wheel. Unfortunately, most grinding wheels are dirty and contaminated with foregn matter and picks up graphit with each revolution.
The outstanding cast iron electrode is Magna 777.
Welds all types of cast iron and steel to cast iron without preheating, gives machinable welds,non-cracking,has higher tensile strength than most types of cast iron